worksheet 7

# worksheet 7 - Worksheet #7 Molar Mass 1. Calculate the...

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Worksheet #7 Molar Mass 1. Calculate the molar mass of the following atoms and compounds: a) Ru; b) Zn; c) Rb; d) Ge; e) C; f) CS 2 ; g) ClF 5 h) N 2 O 5 ; i) BaO; j) CuI 2 ; k) Ca 3 N 2 ; l) Cu(ClO 4 ) 2 6H 2 O Moles 2. Determine the number of moles in each of the following samples: a) 82.5 g N 2 O 4 ; b) 2.6x10 20 molecules NO 2 ; c) 3.78x10 -21 molecules N 2 O 5 . 3. Calculate the total number of atoms in each of the following samples: a) 12.7 mol Ca; b) 0.00361 mol Ne; c) 1.8x10 -12 mol Pu. 4. Determine the mass of the following samples: a) 2.60 mol Cr 2 (SO 4 ) 3 ; b) 8.55x10 22 molecules S 2 F 4 ; c) 8.75x10 25 formula units of Bi(NO 3 ) 3 •5H 2 O; d) 0.57 mol KMnO 4 ; e) 3.8x10 20 molecules NO. Compounds and the Mole 5. What is the number of atoms in the following samples: a) 7.86 kg Al; b) 25.0 g C 6 H 5 OH; c) H atoms in 25.0 g C 6 H 5 OH; d) N atoms in 106 g Mg(NO 3 ) 2 e) 285.3 g cisplatin, Pt(NH 3 ) 2 Cl 2 ; f) H atoms in 44.17 g Pt(NH 3 ) 2 Cl 2 6. In each pair, choose the larger of the two things indicated: a) entities: 0.4 mol O 3 or 0.4 mol O atoms; b) grams: 0.4 mol O 3 or 0.4 mol O; c) moles: 4.0 g N 2 O 4 or 3.3 g of SO 2 ; d) grams: 0.6 mol C 2 H 4 or 0.6 mol F 2 ; e) total ions: 2.3 mol sodium chlorate or 2.3 mol magnesium chloride; f) molecules: 1.0 g of water of 1.0 g H 2 O 2 ; g) Na + ions: 0.250 mol NaBr or 0.0146 kg NaCl; h) grams: 6.022x10 23 atoms 235 U or 6.022x10 23 atoms 238 U. Mass Percents 7. A particular lead-cadmium alloy is 8.0% cadmium by mass. What mass of this alloy, in grams, must you weigh out to obtain a sample contained 6.50x10 23 Cd atoms? 8. Determine the mass percents of the indicated elements in the following forms of penicillin: a)K in penicillin G potassium, C 16 H 17 KN 2 O 4 S; b) S in penicillin S potassium, C 14 H 18 ClKN 2 O 4 S 2 ; c) N in penicillin N, C 14 H 21 N 3 O 6 S; d) C in penicillin G calcium, Ca(C 16 H 17 N 2 O 4 S) 2 . 9. Explain why the following statements are correct or incorrect concerning glucose (blood sugar), C 6 H 12 O 6 . a) The percentages, by mass, of C and O are the same as in CO b) The ratio of C to H to O atoms is the same as in dihydroxyacetone, (CH 2 OH) 2 CO c) The proportions, by mass, of C and O are equal d) The highest percentage, by mass, is that of H

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Chapter 5 - The Mole: A Chemical Conversion Factor Section A 1. Using the Table of Atomic Weights at the beginning of the text, calculate the molecular weight for the following compounds.
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worksheet 7 - Worksheet #7 Molar Mass 1. Calculate the...

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